I would have thought that Kemble was nowhere near capacity usage from my recent visits. The hike in fees while not outrageous is irksome and doesn't bear comparison with equivalent arrangements across the channel.
It would seem more sensible to keep landing fees low and get more traffic, since in GA terms traffic breeds traffic, because we PPLs are a sociable lot.
This ought to be both GA friendly and economically sound.
I hope the new airport management try it out for comparison with the current arrangements since the answer will then be clear and unarguable in the numbers.